Si Abuh is a congregational dawn prayer attendance application that can be used by anyone both from Civil Servants (PNS) or Non-Civil Servants (NON-PNSD), can even be used by the people of Palembang. In 2020 there was a decrease in users of the PNS and NON-PNSD categories with 3,148 users who were no longer active or as much as 30%. This research was conducted to find out one of the causes of the decline in users in terms of usability assessment. This study aims to determine how big the usability level of Si Abuh's application. In this study, variable used is Usability using the System Usability Scale (SUS) method, with the type of research used is descriptive quantitative conducted by involving end users. The weighting of the answer choices for each question in the questionnaire uses a Likert and the calculation of test results using the SUS includes several aspects, namely acceptability, grade scale and adjective rating, with the addition of determining the assessment results by means of SUS score percentile ranking. Based on the results of research on 99 respondents, the average SUS score is 67 with an Ok, Grade D and is in the Marginal High. While the percentile rank is located at the 4th and produces Grade C. Thus, these results indicate that Si Abuh's application is acceptable but still requires improvement to increase usability. Keywords: Si Abuh Application, Usability, System Usability Scale